646261376 has 16 divisors (see below), whose sum is σ = 1287474090. Its totient is φ = 323130624.

The previous prime is 646261373. The next prime is 646261391. The reversal of 646261376 is 673162646.

It can be written as a sum of positive squares in only one way, i.e., 616230976 + 30030400 = 24824^2 + 5480^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a super-2 number, since 2×646261376² = 835307532218826752, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (646261373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2524331 + ... + 2524586.

Almost surely, 2^646261376 is an apocalyptic number.

It is an amenable number.

646261376 is a deficient number, since it is larger than the sum of its proper divisors (641212714).

646261376 is an equidigital number, since it uses as much as digits as its factorization.

646261376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5048931 (or 5048919 counting only the distinct ones).

The product of its digits is 217728, while the sum is 41.

The square root of 646261376 is about 25421.6713848637. The cubic root of 646261376 is about 864.5751200595.

The spelling of 646261376 in words is "six hundred forty-six million, two hundred sixty-one thousand, three hundred seventy-six".